The present invention relates generally to the field of vascular surgery and, more specifically, to an instrument for introducing a vascular aid, such as a vascular prosthesis or implant, into a vessel, e.g. the artery, during surgery.
The international patent application WO 01/13820 discloses such an instrument having two L-shaped elements, first releasable means for locking the two L-shaped elements together so as to form a T-shaped element having a stem and two oppositely directed arms, and second releasable means for connecting the arms of the T-shaped elements along a graft. The second releasable means is a suture encircling at least part of the graft and the arms of the T-shaped element.
Further, the second releasable means comprises an edge for cutting the suture. More precisely, the second releasable means comprises a needle having an edged hole at a tip thereof, through which hole the suture is extended.
Preferably, the T-shaped element has a longitudinal channel in which the needle is positioned. Further, the needle is retractable from the longitudinal channel of the T-shaped element and may have a cap enclosing the free end of the stem in its non-retracted position. Then, the needle and the cap lock the two L-shaped elements to each other.
When releasing the graft the needle is translated in its longitudinal direction, preferably retracted from the stem of the T-shaped element, whereby the edged hole in the tip of the needle cuts the suture extending through that hole. This cutting of the suture releases the graft from the oppositely directed arms of the T-shaped element. By completely removing the needle from the stem of the T-shaped element and also removing the cap, the two L-shaped elements will be released from each other. Finally, the two L-shaped elements may be withdrawn from within the vessel consecutively, leaving the graft in an appropriate position within the vessel.
According to prior art the suture is made to make a turn around the graft close to the tip or free end of each of the oppositely directed arms of the T-shaped element. In order to ensure such a turn each of the oppositely directed arms has a through hole close to its tip and the suture is made to follow a path through that hole. However, when cutting the suture the release may be obstructed by the suture sticking to the through hole.
A first object of the present invention is to further improve an instrument of the above-described type and especially enable its use for introducing a vascular aid into a vessel during surgery.
It is a further object of this invention to provide such an instrument which enables the introduction of such vascular aids as a vascular prosthesis, a vascular implant, a graft connector, a covered stent, a stented graft, a flow occluder and a flow shunt. Vascular aid is used herein as a generic term for these and similar aids.
The instrument may comprise two L-shaped elements, first releasable means for locking the two L-shaped elements so as to form a T-shaped element having a stem and two oppositely directed arms, and second releasable means for connecting the vascular aid along the arms. The free ends of the arms should each have a notch and the second releasable means may comprise a thread to be passed through each of said notches and around said vascular aid and the adjacent arm. As a result, the vascular aid may be introduced into the vessel through a longitudinal incision made therein, said first and second releasable means may be released and said two L-shaped elements may be retracted separately from the vessel.
In a first embodiment, the instrument may be adapted to introduce an elongate vascular aid selected from the group consisting of a graft connector, a covered stent and a stented graft, which vascular aid comprises a sleeve that is to be introduced into the vessel through a longitudinal incision made therein, wherein said thread is tightened around said sleeve so as to keep it compressed during the introduction into the vessel through the longitudinal incision made therein.
Specifically, the graft connector may have a collar projecting radially from the sleeve so as to form a T-shaped tube for connecting a further vessel to the incised vessel. Here, a further thread may be tightened around the collar so as to keep it compressed during the introduction and the thread may be released when the collar has been introduced into an open end of the further vessel. A graft connector of this type is disclosed in e.g. WO 01/13820.
In a second embodiment, the instrument may be adapted to introduce a flow occluder having a bar to be fixed along said arms and introduced into the vessel through a longitudinal incision made therein, said bar having ends capable of blocking flow through said vessel.
In a third embodiment, the instrument may be adapted to introduce a flow shunt having a tube to be fixed along said arms and introduced into the vessel through a longitudinal incision made therein, said tube having open ends so as to allow a flow through said vessel via said tube.
In a fourth embodiment, the instrument may be adapted to introduce a graft connector, which comprises a sleeve that is to be introduced into an open end of each of two opposing vessels, wherein said thread is tightened around said sleeve so as to keep it compressed during the introduction into the open ends of the two vessels, whereafter the first and second releasable means may be released and each of the two L-shaped elements may be retracted from its corresponding vessel.
Preferably, one of said arms is longer than the other one. Then, the longer arm is first introduced into the longitudinal incision in the vessel, whereby the length of the incision does not need to be substantially longer than the length of the shorter arm.
The first releasable means may comprise a cap for enclosing part of said stem and the second releasable means may comprise an edge for cutting said thread.
In a preferred embodiment, the second releasable means comprises a needle having an edged hole at a tip thereof and the cap enclosing the free end of the stem. Also, the two L-shaped elements may form a longitudinal channel for receiving the needle, which is retractable from this channel and which in its non-retracted position locks the two L-shaped elements to each other together with the cap.
According to a second aspect of the invention, an instrument for introducing an elongate vascular aid into a vessel during surgery comprises an L-shaped element having a stem and an arm, and a releasable means for connecting the vascular aid along the arm, whereby the vascular aid may be introduced into the vessel through the open end thereof, said releasable means may be released and said L-shaped element may be withdrawn from the vessel.
According to a further aspect of the invention, a method of introducing an elongate vascular aid into a vessel through a longitudinal incision made therein during surgery comprises the steps of providing two L-shaped elements, locking the two L-shaped elements releasably to each other so as to form a T-shaped element having a stem and two oppositely directed arms each having a notch at a free end thereof, positioning the vascular aid along the arms, passing a thread through the notches and encircling the sleeve and the arms for locking the vascular aid to the arms, inserting the vascular aid through the incision into the vessel using the stem as a holder, releasing the vascular aid from the T-shaped element to allow the vascular aid to remain within the vessel, releasing the L-shaped elements from each other, and retracting the L-shaped elements from the vessel.
The diameter of the elongate vascular aid may be reduced by the releasable locking thereof along the arms of the T-shaped element. Preferably, the vascular aid is released from the T-shaped element by cutting the thread.
According to still another aspect of the invention, a method of introducing an elongate vascular aid into an open end of each of two opposing vessels during surgery comprises the steps of providing two L-shaped elements, locking the two L-shaped elements releasably to each other so as to form a T-shaped element having a stem and two oppositely directed arms each having a notch at a free end thereof, positioning the vascular aid along the arms, passing a thread through the notches and encircling the sleeve and the arms for locking the vascular aid to the arms, inserting the vascular aid into the open ends of the two vessels using the stem as a holder, releasing the vascular aid from the T-shaped element to allow the vascular aid to remain within the two vessels, releasing the L-shaped elements from each other, and retracting the L-shaped elements from the vessels.